Abstract: Seedlings of Zea mays cultured with Hoagland nutrient solutions were treated with different low levels of NaCl ( 0 , 5 , 10 , 20 , 30 mmol􊄯L) . After 30 days treatment , several physiological paramaters were determined , including the content of chlorophyll , the Chla/Chlb ratio, the activity of PEPCase and the photosynthetic rate (Pn) . The results showed that the content of chlorophyll , the Chla/Chlb ratio, the photosynthetic rate and the activity of PEPCase increased under low NaCl level (5 , 10 mmol/L) . It could be concluded that the rise in photosynthesis of Zea mays seedlings under low NaCl level might be related to those changes in the physiological parameters above .

Key words: NaCl